1. Field
The present disclosure relates to a fuel cell.
2. Description of the Related Art
For example, a solid polymer electrolyte fuel cell includes a power generation cell that includes a membrane electrode assembly (MEA) and a pair of separators sandwiching the MEA therebetween. The MEA includes a solid polymer electrolyte membrane made from a polymer ion-exchange membrane, an anode separator disposed on one side of the electrolyte membrane, and a cathode electrode disposed on the other side of the electrolyte membrane. Usually, a fuel cell includes such power generation cells that are stacked each other. For example, the fuel cell is mounted on a fuel-cell electric vehicle and used as an automobile fuel cell system.
In the fuel cell described above, a fuel gas channel (fluid channel), through which a fuel gas (fluid) flows, is formed on a surface of a separator so as face the anode electrode; and an oxidant gas channel (fluid channel), through which an oxidant gas (fluid) flows, is formed on a surface of a separator so as to face the cathode electrode.
A fuel gas inlet manifold, a fuel gas outlet manifold, an oxidant gas inlet manifold, and an oxidant gas outlet manifold extend through peripheral portions of the separators in the stacking direction of the separators. The fuel gas inlet manifold and the fuel gas outlet manifold are fluid manifolds connected to the fuel gas channel. The oxidant gas inlet manifold and the oxidant gas outlet manifold are fluid manifolds connected to the oxidant gas channel. A coolant channel (fluid channel) for cooling the membrane electrode assembly is disposed between the separators. A coolant inlet manifold and a coolant outlet manifold extend through the separators in the stacking direction. The coolant inlet manifold and the coolant outlet manifold are fluid manifolds connected to the coolant channel.
In this case, the fluid channels and the fluid manifolds are connected to each other through connection channels. Each of the connection channels has parallel grooves so that fluid can smoothly and uniformly flow therethrough. For example, Japanese Patent No. 4214027 describes a fuel cell that includes a membrane electrode assembly and a pair of separators sandwiching the membrane electrode assembly therebetween. A bridge portion, which extends from a reactant gas manifold to a reactant gas channel, is disposed between the separators. The bridge portion includes a flat seal, which is disposed on one of the separators, and a plurality of protruding seals, which are disposed on the other separator so as to be in contact with the flat seal. A reactant gas connection channel is formed between the flat seal and the protruding seals, and the reactant gas connection channel connects the reactant gas manifold and the reactant gas channel to each other.
Therefore, the process of assembling the fuel cell can be considerably simplified, and a desirable sealability can be achieved with a simple and economical structure. Moreover, a reactant gas connection channel is formed between the flat seal and the protruding seals, and the reactant gas manifold and the reactant gas channel can be reliably connected to each other through the reactant gas connection channel.